1. Field of the Invention
The present invention relates to connectors for joining the ends of successive lengths of pipe or conduit and/or connecting a pipe or conduit to a housing or other mounting surface wherein the connection will be exposed to axial transverse and bending vibrations. In particular, the present invention relates to connectors for joining pipes to one another or to other structures in exhaust systems for vehicles.
2. The Prior Art
It is well known that, in vehicle exhaust systems, particularly those for heavy duty vehicles, such as large trucks or earth moving equipment, the internal combustion (i.c.) engines produces significant amount of vibration in the exhaust system. Operation of the motors at continuous speeds for prolonged periods of time can, especially, produce what are known as harmonic vibrations which can cause significant deflections in extended lengths of exhaust pipe and at locations where such pipes are mounted to structures such as brackets, engine manifolds, and the like. Repeated deflections and vibration along the exhaust pipe system can, in turn, cause the structures to weaken with time and ultimately fail. Further, such harmonic vibrations can also be transmitted through the exhaust pipes to the mountings of the pipes, promoting the loosening of the mountings, which can result in the sudden displacement of one or more components of the exhaust system, with the potential for both personal injury and equipment damage.
In addition to the vibrations caused by the operation of the motor of the vehicle, an exhaust system is also subjected to various tension, compression and bending forces which also arise during the operation of the vehicle. While individual exhaust system components could be made stronger and more massive to resist failure by fatigue, such constructions would be undesirable due to weight considerations. Further, by making individual elements stiffer, the vibrations are merely transmitted throughout the exhaust system to the mountings or other components and are not reduced or eliminated. Accordingly, it is desirable to isolate the exhaust system, or at least components of the system, from such vibrations and forces.
It is known that if the pipes of an exhaust system are divided and separated by non-rigid connections, rather than being constructed as continuous extended lengths, the development of harmonic vibrations from the motor is precluded or reduced. Such non-rigid connections can be advantageously employed to absorb other tension, compression and bending forces, apart from and in addition to the motor vibration.
It is therefore desirable to provide a connector for joining a length of exhaust pipe, to another pipe or to a mounting, such as an engine manifold, which connector joins the components in a non-rigid fashion and is capable of absorbing tension, compression, and bending forces, as well as the vibrational forces, without transmitting them from one exhaust system component to another.
Typical prior art flexible connectors often require welds at both ends, in order to achieve a strong, substantially fluid-tight connection between the connector and the other exhaust system components to which they are attached. It would be desirable to avoid the use of welds whenever possible, as such welds take time to perform, adding to the installation time of the connector, and increasing the overall assembly time of the vehicle or apparatus to which they are being attached.
In addition, such welds are often difficult to place properly, often requiring additional complexity in the construction of the flexible connector, in order to provide working space for accomplishment of the weld. Still further, there is always the possibility of a small flaw in the weld, leading to possible leakage of harmful exhaust gases, and/or the introduction of a physical weakness in the structure of the flexible connector attachment, leading to the expenditure of additional time for double-checking the quality of each weld being performed.
In some instances, a weld is undesirable, and in order to provide for some form of sealing, gaskets must be positioned at the interface between the flexible connector and the exhaust manifold or other component to which the connector is being attached. Such gaskets which are usually made from mica coated stainless steel, for example, could begin to experience leakage shortly after installation, and, presuming an exhaust manifold pressure in the vicinity of 4.5 psig, could have a leakage rate of over 0.5 liters per minute.
It would be desirable to provide an alternative to welding for the manufacture and/or installation of flexible connector apparatus, which would be less expensive, require less intensive examination upon completion and/or have an enhanced degree of reliability and/or manufacturability than welding techniques.
It would be desirable to provide a flexible connector apparatus and a method and apparatus for the manufacture and installation of same, which would employ fewer welds.
It would also be desirable to provide a weldless connection between a flexible connector apparatus and a component, such as an exhaust manifold, which does not rely upon the use of gaskets, which may deteriorate with use, and which could experience leakage when in use.
These and other objects of the invention will become apparent in view of the present specification including claims, and drawings.